Thermostat.



No. 865,304. PATENTED SEPT. 3, 1907. J. M. HARRISON.

THERMOSTAT.

APPLICATION FILED NOV. 14.1906.

WITNESSES INVENTOR MW 1d, (James ulfffarrzb'aw [i /W Arrows???- JAMES MALBON'HARRISON, QF NEW YORK, N. Y.

THE RMO STAT.

Specification of Letters Patent Patented Sept. 3, 1907.

Application tiled November 14,1906. Serial No. M3375.

To all whom it may concern:

lie it known that I, Janus Anson Hsnmson, a citizen oi the United States, and a resident of the city of New York, borough of Manhattan, in the county and State oi New York, have invented a new and Improved Thermostat, oi which the following isa iull, clear, and exact description.

My invention relates to thermostats, my more particular object being to produce a type of thermostat admitting of general service in the various arts, and

adapted to'producc considerable variations in heavy currents, and yet being peculiarly sensitive in heat. in other words, my special object is to enable com paratively trivial variations in heat to produce great variations in the flow oi a heavy current.

I describe one form oi thermostat embodying my general idea of construction, but it should be understood that I do not limit myselt' to this particular mechanism, as variations therefrom may be made without departing irotn the spirit of my invention.

Reference is to be had to the accompanying drawings lorming a part oi this specification, in which siinilar characters oi rcierence indicate corresponding parts in all the figures.

Figure l-is a front elevation of the device; and Fig. 2

is a central vertical section through the same.

Mounted upon a board 3 is a bracket 4 provided with a bifurcated 0nd 5, the bracket and end together constituting a fork. A pivot (5 passes directly through the lork, and mounted upon this pivot is an elbow 7 provided with an upwardly extending portion 8 having an aperture 9 lherethrough. A pin 10 is provided with a portion ii and is screwed lirmly into the portion '3 so as to project loosely through the aperture 9. The

portion 8 of the elbow 7 is thus prevented from touching the pin. 1\ rod 12 is provided with a scat 13 which supports the under side oi the elbow 7. Lo ated adjacent iu the lower end oi this rod is a bracket 14 which is mounted upon the board 3, the bracket terminating in the threaded bearing 15. A screw '16 passes u pwardly through this threaded bearing and terminates in a cup 17 which supports the lower end of the rod 12. This screw is provided with a milled head 18 whereby it may be turned so as to slightly raise or lower the rod 12.

Anumber of disks '19 of carbon are provided centrally with apertures slipped loosely upon the pin 10. These disks ire normally in light contact, the lines oi demarcation between them being indicated at 20.

Brass disks 21, 22, are disposed respectively adjacent to the board 3, and the upright portion h of the elbow.

"These brass disl's are connected wild conducting wires 23, 24, through which flows the current to be varied by thermostatic action.

My invention is used as follows: The milled head l8 being'turned so as to adjust the rod 12, the portion 8 of the elbow is caused to press the disks together to an extent which may be regulated at will. The instrument being properly adjusted, thereafter works automatically.' The rod 12, in expanding, squeezes tln Carbon disks 19 together and the current passing through the conductors 23, 24, is thus increased. When the rod 12 contracts, the reverse takes place, the current. being cut down.

I find that very slight variations in heat, such (or instance as are produced by the varying tcmporuture of the human hand arc sullicient to elicit enormous variations in the flow oi the current. This is essential for the reason that l desire my thermostat to be able to control currents of a considerable number oi limpet-cs and yet to be in turn controlled by com parat ivcly slight heat variations.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:-

1. The combination ot a plurality of carbon disks providcd with upcrturcs. a pin cxicnding through said upcrturcs for supporting said carbon disks, and hour-controllcd mcchauism for forcing said carbon disks logcthcr with varying dcgrccs of pressure.

2 A thermostat comprising :i nnmbcr of bodies or cou ducting' material provided with npcrtln'cs, a supporting member extending through said apertures for sustaining said bodies. and menus controllab by tcmpcraturc for varying the dcgrcc of prc ire upon said bodies.

3. thermostat compris re; a plurality of bodies of conducting mutt-rial. thc clcctricul rcsistuncc ot' which is sensitive to prcssurc. said bodics bcing provided with npcrturcs, a supporting nicmbcr cxlcndin through said upcrtnrcs l'or sustaining: said bodics. tcni i-r [urn-cork trolled mechanism for varying thc dujn'c f pr surcnpon said bodics, and int-ans controllable at will. (or adjusting said tcmpci'utnrc-conirollcd mcchunisni rcliitivcly to said bodies.

in tcsiimongwhcrcot' l havc signed my name to this specification in thc prc cncc, of' two sub. ribing: witnc."

.lAidli' v HALHON lLUUtlsfUN. 

